It’s a fact—IPv4 addresses are nearing exhaustion. As of February 3, 2011, IANA’s global free pool of IPv4 address was fully depleted and the last five /8 address blocks were simultaneously issued to the five Regional Internet Registries (RIR). In April 2011, APNIC became the first RIR to run out of freely allocated IPv4 addresses. In September 2012, the RIPE NCC became the second regional Internet registry to run out of allocatable IPv4 address space. ARIN and LACNIC are expected to be next (Projected RIR Address Pool Exhaustion Dates). So what does this mean for your company’s network? Migration to IPv6 is no longer if, but when. And, when is closer than you think, so organizations need to be prepared.

IPv6 Migration Overview

The Internet “changing of the guard” from IPv4 to IPv6 will directly affect enterprises since they will have to communicate with their customers, partners, and suppliers over an IPv6 network. As such, it’s critical that businesses understand the implications of IPv6 and how it will affect their organization. Businesses must recognize the following:

  • Enabling IPv6 on the network is needed to maintain continuity of communication for the organization. External websites and other web-facing applications will have to be IPv6-enabled.
  • In the future, new networks may be available only over IPv6 as the remaining IPv4 address space in the last /8 will eventually be exhausted.
  • It is not something that you can just make happen overnight. It takes a considerable amount of time and resources for a successful migration.

Migration Strategy

Let’s start with some interesting, if not alarming, facts around IPv6 adoption as revealed by a recent SolarWinds survey:

  • 47% of respondents said they are “not at all confident” that their company has an actionable IPv6 adoption plan in place
  • Fewer than 3% have completed IPv6 adoption
  • While 69 % have completed no IPv6 migration whatsoever

Regardless of whether you want to be an early adopter or a late mover, the need for a well-thought-out migration strategy is a must. As such, it’s advisable to start building IPv6 into your network’s architectural plan right away. To do this, you will need to consider several key factors, including:

  • The current network environment
  • The amount of IPv6 traffic forecast
  • The availability of IPv6 applications on end systems/appliances

As one would expect, the best approach for a successful IPv6 migration is a phased approach, which will involve managing a hybrid networking environment for IPv4/IPv6 interoperability as you transition.

There are three main transition strategies for handling interoperability between IPv4 and IPv6 networks—dual stack, tunneling, and translation. With that said, dual stack is the recommended strategy for most networks.

Dual Stack Environment

In dual stack environments, devices are able to run IPv4 and IPv6 in parallel:

  • It allows hosts to simultaneously reach IPv4 and IPv6 content.
  • It allows for the greatest flexibility when supporting applications that run over IPv4 and/or IPv6.
  • Dual stack requires all network infrastructure devices to operate both IPv4 and IPv6 protocol stacks and use each stack’s specific routing protocols.

The benefits of dual stack include ease of deployment since both protocols can be run together and still remain independent of each other. This allows for a gradual migration of endpoint devices and applications so organizations can transition at their own pace. Given that most corporate networks utilize private IPv4 addresses on their internal LAN, as opposed to public, routable addresses, organizations can leverage dual stack to transition just their edge network for IPv6 communication while still supporting internal IPv4 traffic. Another advantage of dual stack is that it’s supported by all the major operating system and network vendors. Just keep in mind that dual stack also means having two networks running in parallel. This means doubling your IP management tasks, and in turn, increasing IT expenditures.

To achieve maximum benefit from a dual stack approach, organizations should:

  • Start by migrating the edge network to dual stack.
  • Identify areas or devices to keep out of dual stack to avoid wasting time and resources.
  • Have a well-defined transitional plan with an achievable time limit to complete.


IPv6 is here to stay. Therefore, organizations need to understand how the evolution from IPv4 to IPv6 will affect their business and ensure they take the right steps to prepare their networks for the transition. To be successful in this endeavor, it’s crucial that enterprises:

  • Adopt IPv6 through a phased approach.
  • Identify and assess the highest priority IPv6-critical network areas to determine IPv6 design scope.
  • Develop a design that enables IPv6 to be introduced without disrupting the IPv4 network.
  • Test and implement IPv6 in pilot mode then gradually deploy into production.

By design, IPv4 and IPv6 cannot communicate directly with each other. Network operators will need to run and manage IPv4 and IPv6 networks in parallel in order to ensure that all parts of the Internet remain reachable for everyone. As such, effective IP address management becomes even more imperative.

Do you have a powerful IPAM tool to help you with your IPv6 migration planning? SolarWinds IP Address Manager is a unified platform for DNS, DHCP, and IP address management that can help you streamline your IPv4 to IPv6 transition.